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 * Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
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/*
 * Copyright (c) 2011-2012, Stephen Colebourne & Michael Nascimento Santos
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *  * Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 *
 *  * Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 *  * Neither the name of JSR-310 nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package java.time;

import java.io.Externalizable;
import java.io.IOException;
import java.io.InvalidClassException;
import java.io.ObjectInput;
import java.io.ObjectOutput;
import java.io.StreamCorruptedException;

/**
 * The shared serialization delegate for this package.
 *
 * @implNote This class wraps the object being serialized, and takes a byte representing the type of
 * the class to be serialized.  This byte can also be used for versioning the serialization format.
 * In this case another byte flag would be used in order to specify an alternative version of the
 * type format. For example {@code LOCAL_DATE_TYPE_VERSION_2 = 21}. <p> In order to serialize the
 * object it writes its byte and then calls back to the appropriate class where the serialization is
 * performed.  In order to deserialize the object it read in the type byte, switching in order to
 * select which class to call back into. <p> The serialization format is determined on a per class
 * basis.  In the case of field based classes each of the fields is written out with an appropriate
 * size format in descending order of the field's size.  For example in the case of {@link
 * LocalDate} year is written before month.  Composite classes, such as {@link LocalDateTime} are
 * serialized as one object. <p> This class is mutable and should be created once per
 * serialization.
 * @serial include
 * @since 1.8
 */
final class Ser implements Externalizable {

  /**
   * Serialization version.
   */
  private static final long serialVersionUID = -7683839454370182990L;

  static final byte DURATION_TYPE = 1;
  static final byte INSTANT_TYPE = 2;
  static final byte LOCAL_DATE_TYPE = 3;
  static final byte LOCAL_TIME_TYPE = 4;
  static final byte LOCAL_DATE_TIME_TYPE = 5;
  static final byte ZONE_DATE_TIME_TYPE = 6;
  static final byte ZONE_REGION_TYPE = 7;
  static final byte ZONE_OFFSET_TYPE = 8;
  static final byte OFFSET_TIME_TYPE = 9;
  static final byte OFFSET_DATE_TIME_TYPE = 10;
  static final byte YEAR_TYPE = 11;
  static final byte YEAR_MONTH_TYPE = 12;
  static final byte MONTH_DAY_TYPE = 13;
  static final byte PERIOD_TYPE = 14;

  /**
   * The type being serialized.
   */
  private byte type;
  /**
   * The object being serialized.
   */
  private Object object;

  /**
   * Constructor for deserialization.
   */
  public Ser() {
  }

  /**
   * Creates an instance for serialization.
   *
   * @param type the type
   * @param object the object
   */
  Ser(byte type, Object object) {
    this.type = type;
    this.object = object;
  }

  //-----------------------------------------------------------------------

  /**
   * Implements the {@code Externalizable} interface to write the object.
   *
   * @param out the data stream to write to, not null
   * @serialData Each serializable class is mapped to a type that is the first byte in the stream.
   * Refer to each class {@code writeReplace} serialized form for the value of the type and sequence
   * of values for the type. <ul> <li><a href="../../serialized-form.html#java.time.Duration">Duration.writeReplace</a>
   * <li><a href="../../serialized-form.html#java.time.Instant">Instant.writeReplace</a> <li><a
   * href="../../serialized-form.html#java.time.LocalDate">LocalDate.writeReplace</a> <li><a
   * href="../../serialized-form.html#java.time.LocalDateTime">LocalDateTime.writeReplace</a> <li><a
   * href="../../serialized-form.html#java.time.LocalTime">LocalTime.writeReplace</a> <li><a
   * href="../../serialized-form.html#java.time.MonthDay">MonthDay.writeReplace</a> <li><a
   * href="../../serialized-form.html#java.time.OffsetTime">OffsetTime.writeReplace</a> <li><a
   * href="../../serialized-form.html#java.time.OffsetDateTime">OffsetDateTime.writeReplace</a>
   * <li><a href="../../serialized-form.html#java.time.Period">Period.writeReplace</a> <li><a
   * href="../../serialized-form.html#java.time.Year">Year.writeReplace</a> <li><a
   * href="../../serialized-form.html#java.time.YearMonth">YearMonth.writeReplace</a> <li><a
   * href="../../serialized-form.html#java.time.ZoneId">ZoneId.writeReplace</a> <li><a
   * href="../../serialized-form.html#java.time.ZoneOffset">ZoneOffset.writeReplace</a> <li><a
   * href="../../serialized-form.html#java.time.ZonedDateTime">ZonedDateTime.writeReplace</a> </ul>
   */
  @Override
  public void writeExternal(ObjectOutput out) throws IOException {
    writeInternal(type, object, out);
  }

  static void writeInternal(byte type, Object object, ObjectOutput out) throws IOException {
    out.writeByte(type);
    switch (type) {
      case DURATION_TYPE:
        ((Duration) object).writeExternal(out);
        break;
      case INSTANT_TYPE:
        ((Instant) object).writeExternal(out);
        break;
      case LOCAL_DATE_TYPE:
        ((LocalDate) object).writeExternal(out);
        break;
      case LOCAL_DATE_TIME_TYPE:
        ((LocalDateTime) object).writeExternal(out);
        break;
      case LOCAL_TIME_TYPE:
        ((LocalTime) object).writeExternal(out);
        break;
      case ZONE_REGION_TYPE:
        ((ZoneRegion) object).writeExternal(out);
        break;
      case ZONE_OFFSET_TYPE:
        ((ZoneOffset) object).writeExternal(out);
        break;
      case ZONE_DATE_TIME_TYPE:
        ((ZonedDateTime) object).writeExternal(out);
        break;
      case OFFSET_TIME_TYPE:
        ((OffsetTime) object).writeExternal(out);
        break;
      case OFFSET_DATE_TIME_TYPE:
        ((OffsetDateTime) object).writeExternal(out);
        break;
      case YEAR_TYPE:
        ((Year) object).writeExternal(out);
        break;
      case YEAR_MONTH_TYPE:
        ((YearMonth) object).writeExternal(out);
        break;
      case MONTH_DAY_TYPE:
        ((MonthDay) object).writeExternal(out);
        break;
      case PERIOD_TYPE:
        ((Period) object).writeExternal(out);
        break;
      default:
        throw new InvalidClassException("Unknown serialized type");
    }
  }

  //-----------------------------------------------------------------------

  /**
   * Implements the {@code Externalizable} interface to read the object.
   *
   * @param in the data to read, not null
   * @serialData The streamed type and parameters defined by the type's {@code writeReplace} method
   * are read and passed to the corresponding static factory for the type to create a new instance.
   * That instance is returned as the de-serialized {@code Ser} object.
   *
   * <ul> <li><a href="../../serialized-form.html#java.time.Duration">Duration</a> - {@code
   * Duration.ofSeconds(seconds, nanos);} <li><a href="../../serialized-form.html#java.time.Instant">Instant</a>
   * - {@code Instant.ofEpochSecond(seconds, nanos);} <li><a href="../../serialized-form.html#java.time.LocalDate">LocalDate</a>
   * - {@code LocalDate.of(year, month, day);} <li><a href="../../serialized-form.html#java.time.LocalDateTime">LocalDateTime</a>
   * - {@code LocalDateTime.of(date, time);} <li><a href="../../serialized-form.html#java.time.LocalTime">LocalTime</a>
   * - {@code LocalTime.of(hour, minute, second, nano);} <li><a href="../../serialized-form.html#java.time.MonthDay">MonthDay</a>
   * - {@code MonthDay.of(month, day);} <li><a href="../../serialized-form.html#java.time.OffsetTime">OffsetTime</a>
   * - {@code OffsetTime.of(time, offset);} <li><a href="../../serialized-form.html#java.time.OffsetDateTime">OffsetDateTime</a>
   * - {@code OffsetDateTime.of(dateTime, offset);} <li><a href="../../serialized-form.html#java.time.Period">Period</a>
   * - {@code Period.of(years, months, days);} <li><a href="../../serialized-form.html#java.time.Year">Year</a>
   * - {@code Year.of(year);} <li><a href="../../serialized-form.html#java.time.YearMonth">YearMonth</a>
   * - {@code YearMonth.of(year, month);} <li><a href="../../serialized-form.html#java.time.ZonedDateTime">ZonedDateTime</a>
   * - {@code ZonedDateTime.ofLenient(dateTime, offset, zone);} <li><a
   * href="../../serialized-form.html#java.time.ZoneId">ZoneId</a> - {@code ZoneId.of(id);} <li><a
   * href="../../serialized-form.html#java.time.ZoneOffset">ZoneOffset</a> - {@code (offsetByte ==
   * 127 ? ZoneOffset.ofTotalSeconds(in.readInt()) : ZoneOffset.ofTotalSeconds(offsetByte * 900));}
   * </ul>
   */
  public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException {
    type = in.readByte();
    object = readInternal(type, in);
  }

  static Object read(ObjectInput in) throws IOException, ClassNotFoundException {
    byte type = in.readByte();
    return readInternal(type, in);
  }

  private static Object readInternal(byte type, ObjectInput in)
      throws IOException, ClassNotFoundException {
    switch (type) {
      case DURATION_TYPE:
        return Duration.readExternal(in);
      case INSTANT_TYPE:
        return Instant.readExternal(in);
      case LOCAL_DATE_TYPE:
        return LocalDate.readExternal(in);
      case LOCAL_DATE_TIME_TYPE:
        return LocalDateTime.readExternal(in);
      case LOCAL_TIME_TYPE:
        return LocalTime.readExternal(in);
      case ZONE_DATE_TIME_TYPE:
        return ZonedDateTime.readExternal(in);
      case ZONE_OFFSET_TYPE:
        return ZoneOffset.readExternal(in);
      case ZONE_REGION_TYPE:
        return ZoneRegion.readExternal(in);
      case OFFSET_TIME_TYPE:
        return OffsetTime.readExternal(in);
      case OFFSET_DATE_TIME_TYPE:
        return OffsetDateTime.readExternal(in);
      case YEAR_TYPE:
        return Year.readExternal(in);
      case YEAR_MONTH_TYPE:
        return YearMonth.readExternal(in);
      case MONTH_DAY_TYPE:
        return MonthDay.readExternal(in);
      case PERIOD_TYPE:
        return Period.readExternal(in);
      default:
        throw new StreamCorruptedException("Unknown serialized type");
    }
  }

  /**
   * Returns the object that will replace this one.
   *
   * @return the read object, should never be null
   */
  private Object readResolve() {
    return object;
  }

}
